Those that remain stand on street corners and in suburban plazas like monuments to history, quaint relics of the past and curiosities to children of the 21st century.

"I've never used a pay phone," Jessica Maye, 20, confessed recently while walking downtown. "I tried to use a pay phone once, but it didn't work, I didn't know how to use it."

Advancements in mobile communications technology and reductions in price have put the pay phone on the endangered species list, and the latest figures show how quickly they are vanishing.

Pay phones in the United States numbered 243,487 at the end of last year, the most recent figures available from the Federal Communications Commission. Ten years earlier, more than 1.7 million were installed across the country with more than 2 million at the turn of the century, according to the FCC.

Waiting for a bus in downtown Rochester, Eddie These defied a reporter to spot someone using one of the pay phones a few yards from the bus shelter.

"They're obsolete. They're like dinosaurs," said These, 57, a Rochester resident who recalled last using a pay phone more than 15 years ago.

But just as the likes of Maye and These wonder who still plunks down 50 cents - yes, the cost has doubled in the past decade - to make a call, pay phone operators and trade associations insist pay phones are used and serve an invaluable public function.

"The best numbers we have I think underestimate the number of households in America that have no phone at all," said Randy Nichols, president of the American Public Communications Council. "If somebody doesn't have a phone, the only place they can make a call is the pay phone."

According to the U.S. Census Bureau, nearly 3 million households in the country do not have access to either a landline or cellphone. Residents of those households in many cases rely on borrowing cellphones and pay phones.

James McMullen, 58, of Rochester, is one of those people. He said he uses pay phones every day to place calls to his friends, his doctor, his work and whoever else he may need to reach.

"I use a pay phone just about every day," said McMullen, slapping a thick hand on top of a phone affixed to the Cox Building on St. Paul Street. "I don't use a (cell) phone and I don't have a regular phone, so I use the old iron one."

Another Rochester resident, Randy Tisdale, 33, has a cellphone but said he uses a pay phone every couple of days to save prepaid minutes and money. When he runs out of minutes, he said, he relies on pay phones all the more.

"It's better to have these when you don't have no other phone," Tisdale said, referring to a nearby pay phone.

"I'm not going to sit here and tell you it's a booming, growing business, (but) there's also a public service element to this."- Phil Yawman, Frontier Communications

Locally, roughly 264,000 calls were placed last year from the 3,055 pay phones in the Rochester area, according to Frontier Communications Corp., which operates most of the remaining pay phones in the region. That translates to each phone being used once every four days - a rate well shy of the 80 to 100 calls a month that industry advocates estimate are needed for a pay phone to turn a profit.

But Frontier points out that the phones also facilitated 3,500 free calls to 411 and 911 last year, and the company says those calls are on track to top 5,200 this year.

"I'm not going to sit here and tell you it's a booming, growing business," said Phil Yawman, vice president and general manager of Frontier's greater Rochester market. "But it's still a viable piece of what we do and a business that we remain committed to even thought it's not the growth business it was years ago.

"And there's also a public service element to this," he said. "We believe it's important for everyone in this community to be able to get access to the outside world quickly in a time of need."

Emergencies and natural disasters periodically restore the luster of pay phones as streetscape lifelines. Reports of pay phone usage spiked, for instance, in the aftermath of 9/11 and Hurricane Sandy, when cellphone service was overwhelmed or towers were rendered useless.

Vanessa Ganzler, 30, of Chili, N.Y., recalled being rescued because of a pay phone during her own minor emergency two months ago, when she discovered her cellphone battery had died and she needed to call a taxi. She said the episode reminded her how valuable pay phones could be in a pinch.

"Not every cellphone company is a 'Can you hear me now?'" said Ganzler, referring to the popular Verizon Wireless slogan. "They're not all reliable."